Wednesday April 17, 2013 Happening Now

The FBI is asking for the public's help in the investigation into the Boston Marathon bombings. Law enforcement asking the public for information, photos and video - really anything that can help.

Three are dead. 176 were injured in the twin explosions. Contrary to early reports, there were no other unexploded devices.

We're learning more about the bombs. They were filled with items to be used as shrapnel and places in pressure cookers.. and then placed in nylon backpacks. There's been some pictures of the bombs that have gone public.

We'll also ask various guests about various angles of the investigation.

Rattling more nerves across the country late yesterday. A letter sent to Congressman Roger Wicker tested positive for the poison agent Ricin. It never reached the Capitol, but was intercepted at the off-site mail facility. Some are saying it's unrelated to the Boston bombings, but it's certainly adding to fears. Peter Doocy and Mike Emanuel reporting.

The Senate could take up gun legislation today. Apparently background check provisions are in trouble.

Disturbing news on the bird flu. The World Health Organization says of those infected in China, most didn't have any contact with poultry. Officials are unsure what birds are transmitting the illness, though they also say they do not think it spreads person to person. 77 people have been sickened.

The funeral for former UK Prime Minister Margaret Thatcher was held this morning in London's St Paul Cathedral.

It's the 49th day of testimony in the Jodi Arias murder trial. Defense rested yesterday, and the prosecution is questioning a clinical psychologist to try and debunk the defense's expert testimony.